Vortex fluid amplifier with noise suppresser

ABSTRACT

A fluid vortex amplifier has a pin disposed in the position of the eye of a fluid vortex at the oulet of the vortex chamber so that the pin stabilizes the eye of the vortex and reduces the noise otherwise generated.

United States Patent 1 Randall 1 Mar. 27, 1973 [54] VORTEX FLUIDAMPLIFIER WITH 5 References Cited NOISE SUPPRESSER UNITED STATES PATENTS5 [7 Inventor 32 E Randall worthmgton 3,343,790 9/1967 Bowles ..137/8l.5x 3,424,182 1/1969 Mayer ..137/81.5 Assigneez Ranco Incorporated,Columbus, 3,537,466 11/1970 Chapm ..137/81.5

Ohio

Primary ExaminerWil1iam R. Cline Filed: June 10, 1971 Att0rneyWatts,Hoffmann, Fisher & Heinke 21 A 1 pp NO 151,698 57 ABSTRACT A fluidvortex amplifier has a pin disposed in the posi- [52] US. Cl ..l37/8l.5tion of the eye of a fluid vortex at the oulet of the vor- [51] Int. C1...Fl5c 1/16 x cha ber 50 that the pin stabilizes the eye of the [58]Field of Search ..l37/81.5;73/515,194

vortex and reduces the noise otherwise generated.

6 Claims, 7 Drawing Figures VORTEX FLUID AMPLIFIER WITH NOISE SUPPRESSERBACKGROUND OF THE INVENTION It has been known to control the rate offlow of fluids through a conduit or flow system by creating a vortex inthe flowing fluid. This may be achieved by directing a main flow of thefluid radially in a cylindrical chamber and exiting the fluid through anoutlet opening in an end wall of the chamber and coaxial with thechamber.

The flow of fluid through the chamber may be more or less impeded orrestricted by directing one or more relatively small jets of controlfluid into the main stream of fluid in the chamber so as to impart arotating or vortical movement to the fluid at the outlet of the chamber.This creates a fluid vortex in the chamber with the eye or centerthereof generally more or less centrally of the chamber depending uponthe velocity of the fluid. As the velocity of the vortex increases, theflow of fluid from the chamber is increasingly restricted. Onedisadvantage of fluid amplifiers of the vortex type is that undercertain flow restricting conditions the vortex becomes unstable andproduces an objectionable whistling noise.

THE PRESENT INVENTION An object of the present invention is theprovision of a vortex fluid amplifier of the type mentioned in whichmeans are provided to substantially stabilize the fluid vortex andthereby reduce or minimize the noise produced in the vortex amplifier.

More specifically, the invention comprises providing a fluid vortexamplifier having a cylindrical chamber with a fluid inlet means fordirecting the main fluid flow in a radial direction relative to thecylindrical side walls of the chamber, a fluid outlet in an end wall ofthe chamber substantially coinciding with the axis of the chamber,control fluid jet nozzle means adapted to direct a fluid streamtangentially into the chamber for imparting a vortical movement to thefluid in the chamber, and a pin-like member in the chamber extendingparallel to the axis of the chamber and adjacent the outlet whereby thepin-like member is disposed generally at the eye of the vortex in thechamber, thus stabilizing the vortex.

In other forms of the invention the eye of the vortex formed by thecontrol fluid jet tends to travel along a line radially of the axis ofthe chamber, in which case the axis of the pin-like member is offsetfrom the axis of the chamber midway between the axis of the chamber andthe limit of the normal excursion of the eye of the vortex.

Other objects and advantages of the invention will be apparent from thefollowing description of preferred forms of the invention, referencebeing made to the accompanying drawings wherein:

FIG. 1 is a side elevational view of a fluid vortex amplifier embodyingthe invention;

FIG. 2 is a sectional view taken substantially along line 22 of FIG. 3;

FIG. 3 is a sectional view taken substantially along line 3-3 of FIG. 1;

FIGS. 4 and 5 are schematic views of the amplifier illustrating themanner in which the center of the fluid vortexes shift;

FIG. 6 is a sectional view of another form offluid amplifier, thesection being taken substantially along line 6-6 of FIG. 6; and

FIG. 7 is a sectional view taken substantially along line 7--7 of FIG.6.

Referring to the drawings a pure fluid vortex amplifier 10 is shownwhich, by way of example, may be utilized to modulate the flow ofrefrigerant from the evaporator to the compressor in a refrigerationsystem. The amplifier comprises a chamber 11 having cylindrical sidewalls 12 and is closed by end walls l3, 14. The fluid to be controlledenters the chamber 11 through an inlet tube 15. The axis of the tube 15is substantially normal to the axis of the chamber 11. A fluid outlet 16is formed in the end wall 14 and comprises a tubular diffuser member 17which provides a flare or expansion of the fluid passage as the fluidmoves from the chamber 11. The axis of the opening 16 is coincident withthat of the chamber 11.

A fluid control nozzle 20 is formed in one side of the tubular inlet 15and at the juncture of the tube with the sides 12 of the chamber 11. Thenozzle 20 is adapted to direct a stream of control fluid into the mainstream of fluid entering the chamber through the inlet 15, and thecontrol fluid stream is directed tangentially of the inside of thechamber. The nozzle 20 is connected with a source of fluid, not shown,the flow and pressure of which can be regulated in a convenient manneraccording to the restriction desired to be placed on the flow of thefluid. When fluid is flowing through the chamber 11 while the controlfluid is shut off, the main flow of fluid will pass through the chamberwith relatively little restriction. When control fluid is dischargedfrom the nozzle 20, the main stream of fluid entering the chamber 11through inlet 15 is deflected, and striking the cylindrical walls 12,the fluid is directed into a circular movement which creates a vortex.This action is illustrated in FIG. 4 wherein the arrow M indicates themain fluid stream and the arrow C indicates the control fluid stream.The resulting vortex is indicated by the arrow V. As is well known, thepressure at the center of the vortex is relatively low. Because theoutlet 16 is approximately coaxial with the axis of the vortex,consequently flow from the chamber 11 through the outlet is restrictedby the low pressure area at the outlet. As the force of the controlfluid issuing from nozzle 20increases the velocity of the fluid movingin the vortex increases.

It has been discovered that the axis of the fluid vortex tends to shiftradially with respect to the axis of the chamber 11 as the pressure ofthe control fluid varies. When the control fluid pressure is relativelylow, and a weak vortex results, the center or eye" of the vortex tendsto be relatively substantially offset from the axis of the chamber. Asthe pressure of the control fluid increases and the velocity of thefluid in the vortex increases, a strong" vortex results and its eyemoves more into coincidence with the axis of the chamber I 1. Thiscondition is illustrated in FIG. 5 wherein point El shows the eye of thevortex relative to the axis CA of the chamber 11 when the pressure ofthe control fluid is relatively low and the vortex is weak. E2 shows thevortex eye position when the pressure of the control fluid is at asecond, higher pressure. E3 likewise shows the position of the vortexeye when the control fluid pressure is still higher than that for E2.The eyes E1, E2, E3 of the vortex will generally shift along a line Rwhich extends generally radially of the axis of the chamber. In one formof the invention the angle of line R relative to the angle of the inletfluid jet stream was about 139. This angle might vary according tovariation in the angle of the fluid inlet discharge or the angle of thecontrol jet discharge.

it has been observed that under certain conditions, particularly whenthe velocity of the fluid passing through the amplifier is relativelyhigh, the eye of the vortex oscillates along the line R and relative tothe axis of the outlet port which oscillations produce an objectionablewhistling noise. It has been discovered that by installing a post or pin22 in the chamber 11 and positioned so that its axis is coincident withthe average or mean position of the centers or eyes of the vortexesproduced in the chamber, the vortex positions will be stabilized and thenoise is substantially reduced or eliminated. The pin 22 is suitablysecured at one end to the wall 13 and extends towards the outlet 16,ter-. minating somewhat short thereof. Preferably, the pin 22 has roughsurfaces and in the form shown, the rough surface comprises threads 23formed on the pin. The axis PA of the pin is offset from the axis OA ofthe chamber 11, as seen in FIGS. 2 and 3. The pin 22 is also positionedso that its axis is substantially on the line R which corresponds to thepath along which the vortexes travel in response to different pressuresof the control fluid and the main fluid stream. The distance of the axisof the pin from the axis of the chamber along the line R may bedetermined so as to be approximately the mean position of the range ofexcursions of the eyes of the vortexes of minimum to maximum velocitiesto be encountered.

In operation, the fluid vortexes formed in the chamber 11 tend to formwith the pin 22 at the vortex or eye thereof and to remain relativelyfixed. This eliminates the usual oscillation and the accompanyingwhistle.

A second form of fluid vortex amplifier embodying the invention is shownin FIGS. 6 and 7. The amplifier 30 comprises a chamber 31 formed bycylindrical side walls 32 and circular, flat end walls 33, 34. An inlet35 is formed in the end wall 33 eccentric relative to the axis of thechamber 31. The main flow of fluid is directed into the chamber 31through a suitable conduit 36 secured in the inlet. A fluid outlet 37 isformed in the wall 34 of the chamber coaxial with the axis of thechamber. A suitable conduit 40 is secured in the outlet and receives thefluid discharged from the chamber 31.

A relatively flat circular fluid diverting and control unit 41 isdisposed in the chamber 31. The unit 41 has cylindrical side walls 42and flat ends 43,44. A hollow stem projects from the end 43 of the unit41 and is secured in an opening through the end wall 33 of the chamber31. The stem 45 supports the unit 41 concentric with the chamber 31.Fluid entering the inlet 35 strikes the end 43 of the unit 41 and isdirected radially of the chamber 31, along the inside of walls 32, andthen exits the outlet 37. The main stream of fluid passing thfough thechamber 31 is adapted to assume the form of a vortex by control fluidinjected generally tangentially of the chamber 31 into the chamberthrough four et nozzles 50, 51,52,53 in the side walls 42 of the unit41. Control fluid is fed to the nozzles 50-53 through bores 54,55,56,57,respectively, the inner ends of which bores are open to the interior ofthe stem 45. The control fluid is fed to the stem 45 by any convenientmeans, not shown, and the higher the pressure of the control fluid, thegreater is the velocity of the vortex formed in the chamber 31 by themain stream of fluid. Accordingly, restriction to the flow of fluidthrough the outlet is correspondingly greater.

To maintain stability of position of the fluid vortex, a pin-like member60 is attached to the end 44 of the unit 41. The pin-like member iscoaxial with the axis of the chamber 31 and the outlet 37 and terminatessomewhat short of the entrance to the outlet. The member 60 materiallyreduces the noise otherwise generated by the vortex under usualconditions. Preferably, the member 60 is threaded which presents a roughsurface to the fluid passing through the chamber and appears to improvethe effectiveness of the member in reducing noise.

1 claim:

1. A fluid vortex amplifier comprised of a cylindrical chamber having anoutlet port at one end and substantially coincident with the axis ofsaid chamber, a fluid inlet port in a wall of said chamber, means todirect a main stream of fluid radially in said chamber relative to theaxis of said chamber, and a nozzle structure adapted to direct a controlfluid flow generally tangentially in said chamber for imparting a vortexto said main stream of fluid, characterized by a fixed pin-like memberdisposed in said chamber having its axis substantially parallel to theaxis of said chamber and forming a pivot about which said vortexrotates, said pin-like member having an irregular surface.

2. A fluid amplifier as defined in claim 1 further characterized by saidpin-like member having a threaded surface.

3. A fluid amplifier as defined in claim 1 further characterized by saidfluid inlet port located in a side wall of said chamber and adapted todirect a main stream of fluid radially into said chamber, and saidnozzle structure adapted to direct a control stream of fluid into saidmain stream entering said inlet and generally tangential of saidchamber.

4. A fluid amplifier as defined in claim 1 further characterized by saidpin-like member being concentric with said outlet port.

5. A fluid amplifier as defined in claim 1 further characterized by saidpin-like member being eccentric to said outlet port.

6. A fluid vortex amplifier as defined in claim 1 further characterizedby said inlet port being located in

1. A fluid vortex amplifier comprised of a cylindrical chamber having anoutlet port at one end and substantially coincident with the axis ofsaid chamber, a fluid inlet port in a wall of said chamber, means todirect a main stream of fluid radially in said chamber relative to theaxis of said chamber, and a nozzle structure adapted to direct a controlfluid flow generally tangentially in said chamber for imparting a vortexto said main stream of fluid, characterized by a fixed pin-like memberdisposed in said chamber having its axis substantially parallel to theaxis of said chamber and forming a pivot about which said vortexrotates, said pin-like member having an irregular surface.
 2. A fluidamplifier as defined in claim 1 further characterized by said pin-likemember having a threaded surface.
 3. A fluid amplifier as defined inclaim 1 further characterized by said fluid inlet port located in a sidewall of said chamber and adapted to direct a main stream of fluidradially into said chamber, and said nozzle structure adapted to directa control stream of fluid into said main stream entering said inlet andgenerally tangential of said chamber.
 4. A fluid amplifier as defined inclaim 1 further characterized by said pin-like member being concentricwith said outlet port.
 5. A fluid amplifier as defined in claim 1further characterized by said pin-like member being eccentric to saidoutlet port.
 6. A fluid vortex amplifier as defined in claim 1 furthercharacterized by said inlet port being located in the end wall of saidchamber opposite the end having said outlet port, circular wall means insaid chamber arranged to deflect fluid entering said chamber throughsaid inlet radially of said chamber and said fixed pin-like memberhaving an irregular surface located on said wall means and extendingcoaxially with an outlet port.